True, and they are indeed using antivirals.
They are using Tamiflu, or tamiflu like compounds. WHO has been trying to stop them with some success.
I don't think Bush is looking for some power that is unusual. He only wants something in between calling for marial law by executive order, and doing nothing. He wants the tools he discovered lacking in the Katrina response.
The fact is, that citizens will demand the government do something, and he is anticipating this.
Frankly, there will not be much we can do. We could slow the spread, but not stop it. But discussing it now may bring some measures that will speed up our responses. He can, if he has to,suspend habeous and declare martial law, but there must be a better way.